jhm
Well-Known Member
Johan, thanks for getting us to look at the specs more closely.
I think storage comes down to 5 7kWh Powerwalls. So that gives a max storage of 35kWh. But in ordinary circumstances you'd want to keep the state of charge between 20% and 90% (just like your Model S). So this ordinary usage is 70% of max, 25kWh per day.
What puzzles me is why they have two sizes. If you simply string together twould 30kW units you get all the capacity electrical and physical of one 60kW unit plus and extra 33 kWh/day of solar energy production. Note that the shipping container for one has 20 feet length and the other 40 feet of length. The extra 33 kWh/day of solar panels is really not that expensive. I figure it is about 4.2kW of modules, and at even at $0.75/W, that's an incremental coat of $3150. Given that each Powerwall will have a cost of $3000, skimping on $3150 in panels does not make sense to me. Also it seems the logistics of smaller units may be easier to handle than bigger ones. So I don't understand why someone would prefer buying one larger unit to two smaller units.
I think storage comes down to 5 7kWh Powerwalls. So that gives a max storage of 35kWh. But in ordinary circumstances you'd want to keep the state of charge between 20% and 90% (just like your Model S). So this ordinary usage is 70% of max, 25kWh per day.
What puzzles me is why they have two sizes. If you simply string together twould 30kW units you get all the capacity electrical and physical of one 60kW unit plus and extra 33 kWh/day of solar energy production. Note that the shipping container for one has 20 feet length and the other 40 feet of length. The extra 33 kWh/day of solar panels is really not that expensive. I figure it is about 4.2kW of modules, and at even at $0.75/W, that's an incremental coat of $3150. Given that each Powerwall will have a cost of $3000, skimping on $3150 in panels does not make sense to me. Also it seems the logistics of smaller units may be easier to handle than bigger ones. So I don't understand why someone would prefer buying one larger unit to two smaller units.